Almost one year after first enabling federation, we now federate with other projects for the first time! According to some people’s definition, this finally makes us part of the Fediverse.
It took a lot of work to make this possible, so big thanks to NLnet for funding our full time work on Lemmy, and to @lanodan and @asonix for helping to figure out how Pleroma and Mastodon federation works (it’s difficult because they have almost no documentation).
What is Lemmy?
Lemmy is similar to sites like Reddit, Lobste.rs, or Hacker News: you subscribe to communities you’re interested in, post links and discussions, then vote and comment on them. Lemmy isn’t just a reddit alternative; its a network of interconnected communities ran by different people and organizations, all combining to create a single, personalized front page of your favorite news, articles, and memes.
Major Changes
Federation code rewrite
The rewrite of the federation code started by @nutomic in August is now mostly complete. As a result, the code is much cleaner, and has tests to guarantee no breaking changes between Lemmy versions. As a side effect of this rewrite, it was now relatively easy to enable federation with other projects.
Mastodon and Pleroma users can:
View Lemmy communities, user profiles, posts and comments
Follow Lemmy communities to receive new posts and comments
Replies (mentions) work in both directions, including notifications
In addition, Pleroma users can exchange private messages with Lemmy users.
Note that Pleroma and Mastodon rely on a compatibility mode in Lemmy, which means that they won’t receive events like Deletes or Votes. Other projects whose federation works similar to Pleroma/Mastodon will likely also federate.
Hardcoded slur filter removed
Lemmy finally has essential moderation tools (reporting, user/community blocking), so the hardcoded filter isn’t necessary anymore. If you want to keep using the slur filter, copy these lines to your config file when upgrading, and adjust to your liking.
Upgrade notes
If you installed Lemmy without Ansible, you need to edit the nginx config file to follow this example. Otherwise Mastodon won’t be able to fetch objects or actors from Lemmy. Ansible applies this change automatically.
No other changes are necessary for federation with Mastodon/Pleroma. Just make sure your allowlist/blocklist allows it. Then get started by searching the URL of a Lemmy user or Community in Mastodon.
Note that Mastodon and Pleroma are much, much bigger than Lemmy at this point, with a combined 3 milion users and 4500 instances, compared to 20.000 users and 35 instances for Lemmy (source). The existing mod tools in Lemmy might not be adequate to handle that at the moment.
Be aware that if you have federation enabled in the Lemmy config, Mastodon and Pleroma users can now fetch all posts and comments, to view them and share with their followers. The Lemmy blocklist/allowlist can not prevent this, it only prevents posts/comments from blocked instances to be shown on your own instance. The only solution to this problem is disabling federation, or waiting for signed fetch to be implemented.
If you want to use federation, but review new instances before federating with them, use the allowlist. You can switch from open federation to allowlist federation by pasting the output of the command below into federation.allowed_instances in the Lemmy config.
We’ve now separated our ansible install method (the preferred way to deploy Lemmy) into its own repo, lemmy-ansible. Let us know if you need help migrating existing installations over to it.
Changes
API
There is now a GetUnreadCount in the API to check the count of your unread messages, replies, and mentions.
Short answer, no. Mastodon / microblogging frameworks don’t have the concept of a “post”, which in our activitypub vocabulary is a Page. They only have comments or activitypub Note, where it mentions the previous user with @.
@dessalines you guys have a potential to be much more than just a link aggreagtor.
I maintain that anybody who makes a working, viable groups implementation that covers most of the Fediverse will define the direction of this network for the next five years.
You are the closest so far.
@dessalines I can not follow communities from mastodon, always show “requesting”, any solutions?
Hrm… I’m not sure. I know we have some federation bugs that should get fixed in the release here next week.
Amazing work! How do you feel about Nix flakes deployment?
I don’t know what that is, but anyone is free to package lemmy however they can.
Have you heard of Nix?
Yes, but don’t use it.
@dessalines
Awesome!
Test #3
I was under the impression the slur filter was popular on lemmy? To scare away rightwingers
We still have it turned on for this instance, but its no longer hardcoded.
@dessalines how to view masto posts on lemmy?
You can only see their replies to lemmy posts / comments.
This is my alt that I use on Masto
It’s wild seeing a post on here with 100 likes and comments. Cool.
@dessalines
Finally!
This is a game-changer.
@dessalines Thanks for the work!
This is one of the most critical steps for the Fediverse. Now you are actually breaking new grounds.
Tell me though - can a Mastodon/Pleroma/etc. user create a post in a Lemmy community?
Short answer, no. Mastodon / microblogging frameworks don’t have the concept of a “post”, which in our activitypub vocabulary is a
Page. They only have comments or activitypubNote, where it mentions the previous user with@.@dessalines What’s wrong with publishing a root post a Note? Shouldn’t be too hard.
Or just any type, be it a Page, a Note, a peertube video, or a pixelfed photo?
Posts also have a lot of extra info, things like a link, title, body, community… comments have only a body.
There are a lot of things that aren’t going to match up with community-focused link aggregators and user-focused microblogging ones.
@dessalines you guys have a potential to be much more than just a link aggreagtor.
I maintain that anybody who makes a working, viable groups implementation that covers most of the Fediverse will define the direction of this network for the next five years.
You are the closest so far.
Federation with Smithereen also works, but only one-way for now. There’s something about the way Lemmy signs requests that I need to debug on my side.
Great work!
Question: can only local users post to a group?
No its all federated. Just look at the comments from mastodon in this thread.
Replies seem to work normally. I meant more like top level posts. Ex: https://social.coop/@django/107294367175203267
Those can also be made by other software, but needs to be a
Page(which Mastodon cant send afaik).Amazing work, kudos on the new release!
@dessalines testing commenting from Mastodon 🚀
@lutindiscret @dessalines
This is my test… a sub-comment.
@humanetech
@lutindiscret @dessalines
And my sub-sub-comment 😇
How far can we go! Here’s my sub-sub-sub-comment!